Hair on a Boar's Ass

The phrases "hair on a boars ass" or "boars ass" are used to describe a close call or a situation where great harm (be it physical, mental, financial) is narrowly avoided.
The phrase first became popular in the Midlands within big game hunting groups. A species of wild boars flourished in the untamed forests reaching larger than normal sizes. Often charging at hunters when they wondered too closely. In some cases the boars would miss their targets and the hunters looking up would only see the rear end of a boar before disappearing into the forest thickets.
After The Shattering and militaries began clashing the phrase became more widespread, losing the literal meaning and gaining a more broad explanation of events. The phase was also shortened to "boars ass" for quick exclamation.